Specifies that all of the vars named are dynamic. This specifier affects variable bindings and affects references. All variable bindings affected are made to be dynamic bindings, and affected variable references refer to the current dynamic binding. For example:

special declarations can be either bound declarations, affecting both a binding and references, or free declarations, affecting only references, depending on whether the declaration is attached to a variable binding.

In the contorted code above, the outermost and innermost bindings of y are dynamic, but the middle binding is lexical. The two arguments to + are different, one being the value, which is 3, of the lexical variable y, and the other being the value of the dynamic variable named y (a binding of which happens, coincidentally, to lexically surround it at an outer level). All the bindings of x and references to x are dynamic, however, because of the proclamation that x is always special.